Orbital oncocytoma: evaluation with dynamic contrast-enhanced magnetic resonance imaging using a time-signal intensity curve and positive enhancement integral images.

Oncocytomas, which are benign epithelial tumors filled with abundant mitochondria, arise from ductal cells. Oncocytomas rarely occur in the orbit. We present a case of pathologically proven orbital oncocytoma of the lacrimal gland studied by dynamic contrast-enhanced magnetic resonance imaging (DCE MRI). DCE MRI has potential as an adjunct to conventional MRI in the differential diagnosis and tumor margin delineation of orbital oncocytoma. Simple assessments of the time-signal intensity curve, semiquantitative parameters, and post-processing positive enhancement integral images should be considered in the evaluation of orbital masses found on MRI.